Rod outlines the statistical argument in his blog, which I won’t add to, except to say that the crime figures provided by the Justice Department related to Greater London – they don’t have the figures for London itself (the postal region), which will be far higher.

Rod wasn’t suggesting there was a causal relationship between race and crime, only that young men of West Indian descent were responsible for a disproportionate amount of crime in London. That is a fact, whichever way you wish to dress it up, or ignore the evidence staring you in the face.

All societies need taboos, as Sigmund Freud once said, and in ours race has simply taken the place of sex. We might sneer at pre-sexual revolution Britain and its discomfort with erotic material they wouldn’t wish their servants to read, but we are just as uptight about race. There’s about as much chance of someone honestly discussing black-on-white crime on Radio 4 today as there was of hearing the finer details of the female orgasm on the old Home Service.

The highest praise that a Left-leaning critic can pay an artist is to call his or her work “taboo-breaking”, especially if it deals with sexual matters. But in reality no play about clerical child abuse, Aids or the evils of capitalism is taboo-breaking at all – the artists risk nothing whatsoever, not the friendship of their dinner party guests nor the wrath of the censors or non-existent moral authorities. A taboo is not really a taboo if you risk nothing by breaking it.

In contrast, those who raise indelicate issues about immigration and race soon become hate figures, which is why almost no one in journalism ever seriously asks that most awkward of questions – what has immigration done for us? For someone to do so is a bit like a national figure in the 1950s standing up and saying, “you know what, I actually prefer men” – a risky business that, at worst, can bring about prosecution. Bloggers, often anonymous and unrestrained by either the Editor’s Code of Practice or social taboos, did not have this problem – at least until now.

Immigration has brought many benefits, but it’s also brought many serious problems, which have been aggravated by multiculturalism and the welfare state’s sponsorship of fatherlessness. We should address these honestly.

But multiculturalists and immigrationists want us to ignore any associated problems, because for them diversity is a moral good in itself, an ethical issue in the same way that sexual morality is to Christians. To distract attention from underlying cultural problems caused by attitudes to marriage and religion, they focus on the superficial sounds, smells and colours which immigration brings, even though these are vastly less important.

That is what Rod Liddle meant when he talked about “rap music, goat curry and a far more vibrant and diverse understanding of cultures”. He was not making fun of West Indians – only at Guardian readers who are completely blind to London’s problems. In words that readers of that paper may appreciate, I think he should be applauded for breaking the last taboo.